Page MenuHomec4science
Files F68908580

pair_eam_gpu.cpp
No OneTemporary
Actions

File Metadata

Created
Sat, Jun 29, 10:47

pair_eam_gpu.cpp
View Options

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing authors: Trung Dac Nguyen, W. Michael Brown (ORNL)
------------------------------------------------------------------------- */
#include "math.h"
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "pair_eam_gpu.h"
#include "atom.h"
#include "force.h"
#include "comm.h"
#include "domain.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "memory.h"
#include "error.h"
#include "neigh_request.h"
#include "gpu_extra.h"
using namespace LAMMPS_NS;
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#define MAXLINE 1024
// External functions from cuda library for atom decomposition
int eam_gpu_init(const int ntypes, double host_cutforcesq,
int **host_type2rhor, int **host_type2z2r,
int *host_type2frho,
double ***host_rhor_spline, double ***host_z2r_spline,
double ***host_frho_spline,
double rdr, double rdrho, int nrhor, int nrho,
int nz2r, int nfrho, int nr,
const int nlocal, const int nall, const int max_nbors,
const int maxspecial, const double cell_size,
int &gpu_mode, FILE *screen);
void eam_gpu_clear();
int** eam_gpu_compute_n(const int ago, const int inum_full,
const int nall, double **host_x, int *host_type,
double *sublo, double *subhi, int *tag, int **nspecial,
int **special, const bool eflag, const bool vflag,
const bool eatom, const bool vatom, int &host_start,
int **ilist, int **jnum, const double cpu_time,
bool &success, double *host_fp, double *boxlo,
double *prd, int inum);
void eam_gpu_compute(const int ago, const int inum_full, const int nall,
double **host_x, int *host_type, int *ilist, int *numj,
int **firstneigh, const bool eflag, const bool vflag,
const bool eatom, const bool vatom, int &host_start,
const double cpu_time, bool &success, double *host_fp,
const int nlocal, double *boxlo, double *prd);
int** eam_gpu_compute_energy_n(const int ago, const int inum_full,
const int nall, double **host_x, int *host_type,
double *sublo, double *subhi, int *tag, int **nspecial,
int **special, const bool eflag, const bool vflag,
const bool eatom, const bool vatom, int &host_start,
int **ilist, int **jnum, const double cpu_time,
bool &success, double *host_fp, double *boxlo,
double *prd, double *evdwl, int &inum);
void eam_gpu_compute_energy(const int ago, const int inum_full, const int nall,
double **host_x, int *host_type, int *ilist, int *numj,
int **firstneigh, const bool eflag, const bool vflag,
const bool eatom, const bool vatom, int &host_start,
const double cpu_time, bool &success, double *host_fp,
const int nlocal, double *boxlo, double *prd, double *evdwl);
double eam_gpu_bytes();
/* ---------------------------------------------------------------------- */
PairEAMGPU::PairEAMGPU(LAMMPS *lmp) : PairEAM(lmp), gpu_mode(GPU_FORCE)
{
respa_enable = 0;
cpu_time = 0.0;
}
/* ----------------------------------------------------------------------
check if allocated, since class can be destructed when incomplete
------------------------------------------------------------------------- */
PairEAMGPU::~PairEAMGPU()
{
eam_gpu_clear();
}
/* ---------------------------------------------------------------------- */
double PairEAMGPU::memory_usage()
{
double bytes = Pair::memory_usage();
return bytes + eam_gpu_bytes();
}
/* ---------------------------------------------------------------------- */
void PairEAMGPU::compute(int eflag, int vflag)
{
int i,j,ii,jj,m,jnum,itype,jtype;
double evdwl,*coeff;
evdwl = 0.0;
if (eflag || vflag) ev_setup(eflag,vflag);
else evflag = vflag_fdotr = eflag_global = eflag_atom = 0;
// grow energy and fp arrays if necessary
// need to be atom->nmax in length
if (atom->nmax > nmax) {
memory->destroy(rho);
memory->destroy(fp);
nmax = atom->nmax;
memory->create(rho,nmax,"pair:rho");
memory->create(fp,nmax,"pair:fp");
}
int nlocal = atom->nlocal;
int newton_pair = force->newton_pair;
// zero out density
if (newton_pair) {
m = nlocal + atom->nghost;
for (i = 0; i < m; i++) rho[i] = 0.0;
} else for (i = 0; i < nlocal; i++) rho[i] = 0.0;
// compute density on each atom on GPU
int nall = atom->nlocal + atom->nghost;
int inum, host_start, inum_dev;
bool success = true;
int *ilist, *numneigh, **firstneigh;
if (gpu_mode != GPU_FORCE) {
inum = atom->nlocal;
firstneigh = eam_gpu_compute_energy_n(neighbor->ago, inum, nall, atom->x,
atom->type, domain->sublo, domain->subhi,
atom->tag, atom->nspecial, atom->special,
eflag, vflag, eflag_atom, vflag_atom,
host_start, &ilist, &numneigh, cpu_time,
success, fp, domain->boxlo,
domain->prd, &eng_vdwl, inum_dev);
} else { // gpu_mode == GPU_FORCE
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
eam_gpu_compute_energy(neighbor->ago, inum, nall, atom->x, atom->type,
ilist, numneigh, firstneigh, eflag, vflag, eflag_atom,
vflag_atom, host_start, cpu_time, success, fp,
atom->nlocal, domain->boxlo, domain->prd, &eng_vdwl);
}
if (!success)
error->one(FLERR,"Out of memory on GPGPU");
if (host_start<inum) {
cpu_time = MPI_Wtime();
cpu_compute_energy(host_start, inum, eflag, vflag, ilist, numneigh, firstneigh);
cpu_time = MPI_Wtime() - cpu_time;
}
// communicate derivative of embedding function
comm->forward_comm_pair(this);
// compute forces on each atom on GPU
if (gpu_mode != GPU_FORCE) {
inum = atom->nlocal;
firstneigh = eam_gpu_compute_n(neighbor->ago, inum, nall, atom->x,
atom->type, domain->sublo, domain->subhi,
atom->tag, atom->nspecial, atom->special,
eflag, vflag, eflag_atom, vflag_atom,
host_start, &ilist, &numneigh, cpu_time,
success, fp, domain->boxlo,
domain->prd, inum_dev);
} else { // gpu_mode == GPU_FORCE
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
eam_gpu_compute(neighbor->ago, inum, nall, atom->x, atom->type,
ilist, numneigh, firstneigh, eflag, vflag, eflag_atom,
vflag_atom, host_start, cpu_time, success, fp,
atom->nlocal, domain->boxlo, domain->prd);
}
if (!success)
error->one(FLERR,"Out of memory on GPGPU");
if (host_start<inum) {
double cpu_time2 = MPI_Wtime();
cpu_compute(host_start, inum, eflag, vflag, ilist, numneigh, firstneigh);
cpu_time += MPI_Wtime() - cpu_time2;
}
if (vflag_fdotr) virial_fdotr_compute();
}
void PairEAMGPU::cpu_compute_energy(int start, int inum, int eflag, int vflag,
int *ilist, int *numneigh,
int **firstneigh)
{
int i,j,ii,jj,m,jnum,itype,jtype;
double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
double rsq,r,p,rhoip,rhojp,phi;
double *coeff;
int *jlist;
double **x = atom->x;
double **f = atom->f;
int *type = atom->type;
int nlocal = atom->nlocal;
int newton_pair = force->newton_pair;
// rho = density at each atom
// loop over neighbors of my atoms
for (ii = start; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
if (rsq < cutforcesq) {
jtype = type[j];
p = sqrt(rsq)*rdr + 1.0;
m = static_cast<int> (p);
m = MIN(m,nr-1);
p -= m;
p = MIN(p,1.0);
coeff = rhor_spline[type2rhor[jtype][itype]][m];
rho[i] += ((coeff[3]*p + coeff[4])*p + coeff[5])*p + coeff[6];
}
}
}
// communicate and sum densities
if (newton_pair) comm->reverse_comm_pair(this);
// fp = derivative of embedding energy at each atom
// phi = embedding energy at each atom
for (ii = start; ii < inum; ii++) {
i = ilist[ii];
p = rho[i]*rdrho + 1.0;
m = static_cast<int> (p);
m = MAX(1,MIN(m,nrho-1));
p -= m;
p = MIN(p,1.0);
coeff = frho_spline[type2frho[type[i]]][m];
fp[i] = (coeff[0]*p + coeff[1])*p + coeff[2];
if (eflag) {
phi = ((coeff[3]*p + coeff[4])*p + coeff[5])*p + coeff[6];
if (eflag_global) eng_vdwl += phi;
if (eflag_atom) eatom[i] += phi;
}
}
}
/* ---------------------------------------------------------------------- */
void PairEAMGPU::cpu_compute(int start, int inum, int eflag, int vflag,
int *ilist, int *numneigh,
int **firstneigh)
{
int i,j,ii,jj,m,jnum,itype,jtype;
double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
double rsq,r,p,rhoip,rhojp,z2,z2p,recip,phip,psip,phi;
double *coeff;
int *jlist;
double **x = atom->x;
double **f = atom->f;
int *type = atom->type;
int nlocal = atom->nlocal;
int newton_pair = force->newton_pair;
// compute forces on each atom
// loop over neighbors of my atoms
for (ii = start; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
if (rsq < cutforcesq) {
jtype = type[j];
r = sqrt(rsq);
p = r*rdr + 1.0;
m = static_cast<int> (p);
m = MIN(m,nr-1);
p -= m;
p = MIN(p,1.0);
// rhoip = derivative of (density at atom j due to atom i)
// rhojp = derivative of (density at atom i due to atom j)
// phi = pair potential energy
// phip = phi'
// z2 = phi * r
// z2p = (phi * r)' = (phi' r) + phi
// psip needs both fp[i] and fp[j] terms since r_ij appears in two
// terms of embed eng: Fi(sum rho_ij) and Fj(sum rho_ji)
// hence embed' = Fi(sum rho_ij) rhojp + Fj(sum rho_ji) rhoip
coeff = rhor_spline[type2rhor[itype][jtype]][m];
rhoip = (coeff[0]*p + coeff[1])*p + coeff[2];
coeff = rhor_spline[type2rhor[jtype][itype]][m];
rhojp = (coeff[0]*p + coeff[1])*p + coeff[2];
coeff = z2r_spline[type2z2r[itype][jtype]][m];
z2p = (coeff[0]*p + coeff[1])*p + coeff[2];
z2 = ((coeff[3]*p + coeff[4])*p + coeff[5])*p + coeff[6];
recip = 1.0/r;
phi = z2*recip;
phip = z2p*recip - phi*recip;
psip = fp[i]*rhojp + fp[j]*rhoip + phip;
fpair = -psip*recip;
f[i][0] += delx*fpair;
f[i][1] += dely*fpair;
f[i][2] += delz*fpair;
if (eflag) evdwl = phi;
if (evflag) ev_tally_full(i,evdwl,0.0,fpair,delx,dely,delz);
}
}
}
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairEAMGPU::init_style()
{
if (force->newton_pair)
error->all(FLERR,"Cannot use newton pair with eam/gpu pair style");
if (!allocated) error->all(FLERR,"Not allocate memory eam/gpu pair style");
// convert read-in file(s) to arrays and spline them
file2array();
array2spline();
// Repeat cutsq calculation because done after call to init_style
double maxcut = -1.0;
double cut;
for (int i = 1; i <= atom->ntypes; i++) {
for (int j = i; j <= atom->ntypes; j++) {
if (setflag[i][j] != 0 || (setflag[i][i] != 0 && setflag[j][j] != 0)) {
cut = init_one(i,j);
cut *= cut;
if (cut > maxcut)
maxcut = cut;
cutsq[i][j] = cutsq[j][i] = cut;
} else
cutsq[i][j] = cutsq[j][i] = 0.0;
}
}
double cell_size = sqrt(maxcut) + neighbor->skin;
int maxspecial=0;
if (atom->molecular)
maxspecial=atom->maxspecial;
int success = eam_gpu_init(atom->ntypes+1, cutforcesq,
type2rhor, type2z2r, type2frho,
rhor_spline, z2r_spline, frho_spline,
rdr, rdrho, nrhor, nrho, nz2r, nfrho, nr, atom->nlocal,
atom->nlocal+atom->nghost, 300, maxspecial,
cell_size, gpu_mode, screen);
GPU_EXTRA::check_flag(success,error,world);
int irequest = neighbor->request(this);
neighbor->requests[irequest]->half = 0;
neighbor->requests[irequest]->full = 1;
}

Event Timeline

c4science · Help